/*
 * Copyright (c) 2011-2012 Tygron Serious Gaming
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * * Neither the name of 'Swing to Nifty Converter' nor the names of its contributors
 *   may be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package nl.tygron.niftyconverter.loader;

import java.awt.Component;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.logging.Logger;
import javax.tools.JavaCompiler;
import javax.tools.ToolProvider;
import nl.tygron.niftyconverter.util.NiftyUtils;

/**
 * @author Jeroen Warmerdam
 * @Specialism
 * @Maintainer Jeroen Warmerdam
 */
public class ComponentSourceLoader extends ComponentLoader {

	private static final Logger logger = Logger.getLogger(ComponentSourceLoader.class.getName());

	private static final String compilerDirName = "scratch";
	private static final String compilerOutputNeedle = "[wrote";

	/*
	 * (non-Javadoc)
	 * @see nl.tygron.niftyconverter.loader.ComponentLoader#loadComponent(java.io.File)
	 */
	@Override
	public Component loadComponent(File resourceFile) {

		String sourceFile = resourceFile.toString();

		File destinationDir = new File(compilerDirName);
		if (!destinationDir.exists()) {
			destinationDir.mkdirs();
		}
		String destinationDirName = destinationDir.toString();
		String[] options = new String[] { "-d", destinationDirName, "-verbose", sourceFile };

		JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
		if (compiler == null) {
			logger.warning("Cannot find java compiler. Source files can only be loaded when run from JDK.");
		}

		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		int result = compiler.run(System.in, System.out, baos, options);

		if (result != 0) {
			logger.warning("Could not compile [" + sourceFile + "]");
			return null;
		}

		ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
		BufferedReader reader = new BufferedReader(new InputStreamReader(bais));
		String wroteLine = null;
		try {

			String line = reader.readLine();
			while (line != null) {
				if (line.startsWith(compilerOutputNeedle)) {
					wroteLine = line;
				}
				line = reader.readLine();
			}

			reader.close();
			bais.close();
			baos.close();

		} catch (IOException e) {
			e.printStackTrace();
		}

		if (wroteLine == null) {
			logger.warning("Could not find where compiler saved file");
		}
		// Add 1 for the whitespace and directory start
		int startIndex = compilerOutputNeedle.length() + 1;

		// Subtract 1 for the trailing ]
		int length = wroteLine.length() - 1;
		String classDirString = wroteLine.substring(startIndex, length);
		File classFile = new File(classDirString);

		// Now find the class name
		String className = classDirString.substring(compilerDirName.length() + 1);
		className = className.replace("." + LoaderFactory.EXTENSION_COMPILED, "");
		className = className.replace(File.separatorChar, '.');

		Component component = null;
		try {

			URL[] classUrls = { destinationDir.toURI().toURL() };
			URLClassLoader ucl = new URLClassLoader(classUrls, ComponentSourceLoader.class.getClassLoader());
			Class<?> clazz = Class.forName(className, true, ucl);
			component = loadFromClass(clazz);

		} catch (Exception e) {
			e.printStackTrace();
		}

		// Clean up
		try {
			NiftyUtils.delete(destinationDir);
		} catch (IOException e) {
			e.printStackTrace();
		}

		return component;
	}
}
